Abstract
The nonlinear DC and RF properties of HBTs were modeled using a customized Gummel-Poon-basedlarge signal model. The characterization and modeling techniques presented here were validated usingPNP InP-based HBTs, which manifest highly nonlinear features. On-wafer pulsed DC measurements wereperformed on these HBTs in order to extract various second-order effects. These pulsed measurementsindicated the presence of distributed thermal resistances and thermal capacitances. An analytical parameterextraction procedure was then used to extract model data from measured small-signal S-parameters andfrom the DC characteristics. Pulsed characteristics under different pulse widths and different substratetemperatures were employed to complete the model extraction. Good agreement was obtained between themodeled and measured DC, pulsed, small-signal, and large-signal microwave characteristics. The approachdeveloped in this work is useful for modeling of highly nonlinear HBT characteristics, and it is directlyapplicable to the HBT power amplifiers often encountered in wireless communication circuits and systems.